The purpose of this project is to quantify the various dc potentials that can be recorded from the mammalian cochlea in response to sound stimulation. These dc potentials are an aggregate response, composed of several components, all of which presumably originate in different sources and have their genesis in different mechanisms within the cochlea. Our purpose is to identify these mechanisms and sources, and to delineate the significance of these dc components in the hearing process. We also seek to record and identify the generator potential of the cochlea, which is hypothesized to be the direct precursor of the all-or-none discharges in the auditory nerve. Finally, we are studying the properties of the compound action potential of the auditory nerve, and seek to correlate changes in this response with experimentally induced cochlear pathology.